The nested data structure inherent in education (i.e. students nested in schools nested in districts) makes intact school matching an appealing approach in observational studies of educational interventions and policies for both theoretical and practical purposes. This paper provides guidance to applied education researchers who are employing…

Despite the existence of a considerable and current educational literature concerned with the effect of class size on student achievement, the results of attempts to empirically identify the relationship between the variables class size and student achievement are mixed at best. These attempts have typically been hindered, however, by the…